Covers the six human hepatitis viruses A, B, C, D, E and G, starting with a comparison table of genome type, family, envelope, transmission and chronicity. It then takes each virus in turn, covering its biology, transmission, incubation, clinical course, serological diagnosis, prevention and treatment, with the HBV serology markers set out separately and the HDV coinfection and superinfection distinction noted.
Topic 100 of 113 in the MU Sofia syllabus for Microbiology (Medicine, Year 3). The free AceMed note covers it in 8 sections, about 291 words (3 min of reading), with 15 flashcards.
In this note
Human Hepatitis Viruses: A, B, C, D, E, G
I. Overview of Hepatitis Viruses
Hepatitis A Virus (HAV)
Hepatitis B Virus (HBV)
Hepatitis C Virus (HCV)
Hepatitis D Virus (HDV)
Hepatitis E Virus (HEV)
Hepatitis G Virus (HGV / GBV-C)
Hepatitis A Virus (HAV)
RNA virus, non-enveloped, from Picornaviridae
Stable in environment; resistant to heat and acid
Transmitted via fecal-oral route (contaminated water/food)
Short incubation: 2–6 weeks
Clinical course:
Self-limiting acute hepatitis
No chronicity
Fever, malaise, anorexia → jaundice, hepatomegaly
Diagnosis: anti-HAV IgM (acute), IgG (past infection or vaccine)
Prevention: Inactivated vaccine, hygiene
Hepatitis B Virus (HBV)
Partially double-stranded DNA virus, enveloped
Unique reverse transcriptase activity (but is a DNA virus)
Transmission: blood, sexual contact, perinatal
Incubation: 4–12 weeks
Pathogenesis:
Damage is immune-mediated (CD8+ T cells attacking infected hepatocytes)
Can cause chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC)
Serology:
HBsAg = infection
anti-HBs = immunity
anti-HBc IgM = acute infection
anti-HBc IgG = prior exposure
HBeAg = active replication/high infectivity
Prevention:
Recombinant vaccine (HBsAg)
Neonatal prophylaxis: vaccine + HBIG
Treatment: Tenofovir, Entecavir, Peg-IFN-α
Hepatitis C Virus (HCV)
RNA virus, enveloped, from Flaviviridae
High genetic variability → no vaccine
Transmission: bloodborne (transfusions, IVDU, less sexual)
